|Número de publicación||US5858666 A|
|Tipo de publicación||Concesión|
|Número de solicitud||US 08/697,871|
|Fecha de publicación||12 Ene 1999|
|Fecha de presentación||29 Ago 1996|
|Fecha de prioridad||29 Ago 1996|
|También publicado como||WO1998009168A1|
|Número de publicación||08697871, 697871, US 5858666 A, US 5858666A, US-A-5858666, US5858666 A, US5858666A|
|Inventores||Paul S. Weiss|
|Cesionario original||Biotechnology Research And Development Corporation, The Penn State Research Foundation|
|Exportar cita||BiBTeX, EndNote, RefMan|
|Citas de patentes (17), Otras citas (1), Citada por (69), Clasificaciones (15), Eventos legales (5)|
|Enlaces externos: USPTO, Cesión de USPTO, Espacenet|
The invention relates in general to techniques for detecting substances immobilized to a substrate, and in particular to a method and apparatus employing a sensor array operated at AC frequencies.
With the advent of the human genome project and other gene sequencing technologies, techniques for performing sequencing has been of great interest. There are many other medical, biological and analytical applications for sensor arrays. One sequencing technique involves the detection of fluorescently labelled materials, such as that described in U.S. Pat. No. 5,143,854. Such devices typically include a microscope and a monochromatic or polychromatic light source for directing light at a substrate. A photon counter detects fluorescence from the substrate, while an x-y translation stage varies the location of the substrate. A computer controls the movement of the x-y translation table and data collection. Light from the light source is focused at a substrate surface by manually adjusting the microscope. Manual adjustment may be time consuming and inconvenient. Furthermore, due to the inherent imperfections present in the x-y translation table and substrate, the substrate may be out of focus when it is moved by the table so that the data collected may be inaccurate.
Other devices for detecting fluorescently labelled materials employ charge coupled devices instead of microscopes. While such devices avoid the need for many adjustments of the microscope, such devices have limited resolution. In some sensor units available commercially, each sensor unit typically has dimensions of 20 microns by 20 microns.
It is therefore desirable to provide an improved technique for detecting immobilized substances on a substrate where the above-described difficulties and limitations are avoided.
One aspect of the invention is directed towards an apparatus for detecting a target, comprising a transducer having a two-dimensional array of detection locations; probes immobilized at sites that are at or close to the locations for combination with the target to form a complex; and means for applying AC electrical signals to the locations to detect said target.
Another aspect of the invention is directed towards a method for detecting a target, comprising the steps of: providing a transducer having a two-dimensional array of detection locations and probes immobilized at sites at or close to the locations for combination with the target to form a complex and causing said target to be at or close to at least one of the locations. The method further comprises applying AC electrical signals to said at least one of said locations and detecting an AC electrical signal at or close to said at least one of said locations to detect said target.
Yet another aspect of the invention is directed towards a method for making a transducer having a two-dimensional array of detection locations to detect a target. The method comprises the steps of immobilizing probes at sites at or close to the locations for combining with the target to form a complex having a characteristic frequency; determining said characteristic frequency and selecting a transducer for applying AC electrical signals at said locations, said transducer being adapted to transmit at said characteristic frequency.
FIG. 1 is a top view of a portion of a transducer for detecting targets immobilized on a substrate to illustrate the preferred embodiment of the invention.
FIG. 2A and 2B are schematic views of horizontal and vertical transmission lines in the transducer of FIG. 1 to illustrate the preferred embodiment of the invention.
FIG. 3 is a cross-sectional view of the transducer of FIGS. 1, 2A, 2B showing two sets of transmission lines on respectively a top and a bottom portion that can be placed in close proximity to illustrate the preferred embodiment of the invention.
FIG. 4 is a schematic circuit diagram of an apparatus for detecting targets immobilized on a substrate to illustrate the preferred embodiment of the invention.
FIG. 5 is a schematic view to illustrate a process for addressing the transducer of FIGS. 1, 2A, 2B, 3 to illustrate the preferred embodiment of the invention.
FIG. 6 is a schematic view of a flow cell for causing a target substance to be in close proximity to a transducer and a detector to illustrate the preferred embodiment of the invention.
FIG. 7 is a schematic view of a transducer such as that of FIG. 1 with empty probes to illustrate the preferred embodiment of the invention.
FIG. 8 is a schematic view of a transducer such as that of FIG. 1 with filled probes to illustrate the preferred embodiment of the invention.
FIG. 9 is a schematic view of transducer such as that of FIG. 1 where the probes have been filled with tagged target substances.
FIG. 10 is a schematic view of the transducer of FIG. 1 employing a plurality of probes some of which are empty and some of which are filled to illustrate the preferred embodiment of the invention.
FIG. 11 is a schematic view of the transducer of FIG. 10 where the empty probes as shown in FIG. 10 have been filled with tagged target substances to illustrate the preferred embodiment of the invention.
FIG. 12 is a schematic view of the transducer of FIG. 1 employing a plurality of alternating current scanning tunneling microscope (ACSTM) sensor tips instead of two arrays of wires to illustrate an alternative embodiment of the invention.
For simplicity in description, identical components are labelled by the same numerals in the different figures of this application.
The following terms are intended to have the following general meanings as they are used herein:
1. Complementary: Refers to the topological or chemical compatibility or matching together of interacting of a probe molecule and its target. Thus, the target and its probe, defined below, can be described as complementary, and, furthermore, the contact surface characteristics are complementary to each other.
2. Probe: A probe is a molecule or molecular complex that is recognized by a particular target. Examples of probes that can be investigated by this invention include, but are not restricted to, agonists and antagonists for cell membrane receptors, toxins and venoms, viral epitopes, hormones (e.g, opiates, steroids, etc.), hormone receptors, peptides, enzymes, enzyme substrates, cofactors, drugs, lectins, sugars, oligonucleotides, nucleic acids, oligosaccharides, proteins, and monoclonal antibodies.
3. Target: A target is a molecule that has an affinity for a given probe. Targets may be naturally-occurring in their unaltered state or as aggregates with other species. Targets may be attached, covalently or noncovalently, to a binding member, either directly or via a specific binding substance. Examples of targets which can be employed by this invention include, but are not restricted to, antibodies, cell membrane receptors, monoclonal antibodies and antisera reactive with specific antigenic determinants (such as on viruses, cells, or other materials), drugs, polynucleotides, nucleic acids, peptides, cofactors, lectins, sugars, polysaccharides, cells, cellular membranes, and organelles. Targets are sometimes referred to in the art as anti-probes. As the term targets is used herein, no difference in meaning is intended. A "Probe Target Pair" is formed when two molecules or molecular complexes have combined through molecular recognition to form a complex.
Applicant has discovered that, by employing a transducer that has a two-dimensional array of detection locations with probes immobilized at such locations, and by transmitting AC electrical signals to such locations, a target bound to one or more of the probes can be detected. In the preferred embodiment, the frequency of the AC electrical signal is tuned to a characteristic frequency of one of the probes, or of a complex formed by a target and a probe, so that the presence or absence of the target can be determined without using fluorescent or other labels. In the preferred embodiment, the AC signals are transmitted to the locations by means of two sets of intersecting transmission lines, where the spacing between adjacent lines in each set of lines is of the order of one micron or less so that the target can be detected at high resolution but without the disadvantages requiring the confocal microscopes or other optical means for detecting a fluorescently labelled target as in the above-described prior art systems.
FIG. 1 is a top view of a bottom portion 20 of a transducer, where portion 20 comprises a substrate 22 onto which a number of probes 24 have been attached for binding to the target to be detected. Probes 24 may be in the shape of elongated strands, such as strands of polymers (e.g. DNA), although symbolically, the probes have been shown as square blocks in FIG. 1. Not shown in FIG. 1 is a set of horizontal transmission lines shown in FIG. 2A. Thus, to construct the bottom unit 20 of the transducer, a set of horizontal transmission lines 32 are first fabricated on a substrate 22. Lines 32 are made of an electrically conductive material such as metal.
Transmission lines 32 are preferably parallel to one another, and so are lines 42 of FIG. 2B. In the preferred embodiment shown in FIGS. 2A, 2B, lines 32 are orthogonal to lines 42. It will be understood that this is not required and the lines 32 can simply be transverse to lines 42.
In the preferred embodiment, lines 32 may be made of gold and may be fabricated using masks and lithographic techniques commonly used in the semiconductor industry. The lines can also be fabricated using ink jet printing or other technologies. The spacing 32' between adjacent lines 32 can be made as small as required, by lithographic or other techniques used in the semiconductor or other industries. Then the probes 24 are attached to selected locations on the transmission lines 32. This may be accomplished as follows. First, linker molecules are attached to selected locations along one or more of the transmission lines 32. For example, thiol gold chemical techniques may be used to attach a probe to each linker molecular, such as an ω-functionalized alkane thiol, to form the probes 24 as shown in FIG. 1.
As shown in FIG. 1, probes 24 are attached at regular spacings along each of the horizontal transmission lines 32 to maximize the number of probes that can be attached to the substrate 22. Substrate 22 may be made of an electrically insulating and stable material such as glass or silica, or may be a metallic or semiconductor material with an insulating layer.
The top unit 40 of the transducer comprises a substrate 22' similar to substrate 22 and vertical transmission lines 42 fabricated on substrate 22' also using masks, lithographic techniques or ink jet printing or other techniques. The top and bottom units of the transducer can then be assembled together by means of a holder as shown in FIG. 3. FIG. 3 is a cross-sectional view of the transducer 50 comprising the top unit 40, the bottom unit 20 and the bottom holding portion 46 for holding the bottom unit 20 and a top holding portion 48 for holding the top unit 40. Portions 46, 48 may be connected by means of a hinge or alignment post 52 so that when the two portions are moved towards each other, the two units 20, 40 will be in close proximity to each other with the probes 24 lying between the horizontal and vertical transmission lines 32, 42. Portions 46, 48 can be made such that they permit passage of a fluid between the bottom and top units 20, 40. Alternatively, the top unit 40 can be made a part of the bottom unit by microfabrication techniques. In this case, hollows could be made between the horizontal and vertical transmission lines 32, 42.
The overall detection system is illustrated in FIG. 4. As shown in FIG. 4, the two sets of transmission lines 32, 34 are addressed respectively by two AC sources 62 and 64 respectively, through multiplexers 66, 68. In the preferred embodiment multiplexer 66 applies AC signals sequentially to one horizontal transmission line at a time in a scanning operation, scanning through all of the horizontal transmission lines one at a time. Multiplexer 68 is such that the AC signals from source 64 are applied sequentially to scan the vertical transmission lines 42, one at a time. Therefore, at any one time, electrical signals are applied on both sides of a probe only at the intersection of a vertical transmission line and a horizontal transmission line as illustrated in FIG. 5. As shown in FIG. 5, multiplexer 66 causes an AC signal of frequency f1 to be applied sequentially to each one of the horizontal transmission lines 32, and multiplexer 68 causes an AC signal of frequency f2 to be applied sequentially to each one of the vertical transmission lines 42. In FIG. 5, showing a particular instance in time in the scanning operation of both the horizontal and vertical sets of transmission lines, multiplexer 66 causes an AC signal of frequency f1 to be applied to one of the horizontal transmission lines 32a, and multiplexer 68 causes an AC signal of frequency f2 to be applied to one of the vertical transmission line 42a. Then, of all the probes 24, only the one 24a in between and overlapping the intersection of lines 32a, 42a will respond to and affect or change the signals applied to the two lines. Thus this particular probe that is being so tested is an individual sensor unit 60 at the intersection of transmission lines 32a, 42a as shown in FIG. 5, where all the remaining probes do not affect or respond to the signals applied. This is a particularly advantageous way for addressing a particular probe, and simplifies the construction and operation of the detection scheme.
In the case where there is some crosstalk between units, the largest effect still comes from probe 24a. The contributions from neighboring units 24 can be deconvoluted once they and their neighbors have been probed. Similarly for overwhelming signals due to crosstalk, duplication of substantially identical units with different neighbors in the transducer can be used to determine the presence or concentration of particular targets.
While the embodiment of FIGS. 1, 2A and 2B illustrates a transducer where the probes are attached to the bottom unit and not to the top unit, it will be understood that they can be attached to the top unit instead; such and other variations are within the scope of the invention. Instead of employing two separate substrates for supporting the two sets of transmission lines, it may be possible to support the two sets in a single substrate such as silicon. Such and other variations are within the scope of the invention. Where the substrates 22, 22' (or a single piece of semiconductor material substrate) are made of semiconductor material or a material on which semiconductors can be grown, it is also possible to fabricate the entire system in FIG. 4 on the substrates).
In reference to FIG. 5, the signals on the two transmission lines 32a, 42a will mix so that if the frequencies f1, f2 themselves or any algebraic sum of or difference between them (given by the algebraic combination Af1 +Bf2 where A, B may be zero or positive or negative integers) match (substantially equal to) the characteristic frequency of a probe or of a complex formed by a probe and a target or a label, such probe or complex or label will cause a change in the signal at the frequencies transmitted to the individual sensor unit 60. Such change in signal can be detected by means of a detector 70 in FIG. 4.
The detector 70 is preferably placed in close proximity to each of the individual sensor units to sense a change in signal and may comprise a solid piece of metal or a structure similar to that of detector 50 but without the probes. Since the addressing of a particular probe is accomplished by the two sets of transverse transmission lines, the construction of the detector can be less critical. The signals sensed by the detector 70 are then sent to a detector circuit 80 for analysis. In the preferred embodiment, the detector circuit may be a spectrum analyzer although a lock in amplifier or simply a filter may suffice in some situations. Detector 70 may be held in close proximity to transducer 50 by any suitable means, such as by clamping them together or by attaching them using an adhesive, or by fabricating them together. In some cases, transmission lines 32, 42 can serve as the detector.
FIG. 6 is a schematic view of a system for causing the target to bind to one or more of the probes. As shown in FIG. 6, system 100 includes a flow cell 102 having an inlet port 104 and an outlet port 106. A pump 110 pumps a fluid from storage 112 through the inlet port 104 to the flow cell 102. The fluid circulates through the flow cell and exits through the outlet port 106 to another storage 114.
The fluid 120 in flow cell 102 may contain a target that is to be detected or measured. When transducer 50 is placed in flow cell 102, the target that may be present in fluid may bind to one or more of the probes 24 in transducer 50. Then when AC signals are applied in the manner described above to individual sensor units 60 sequentially in the transducer 50, and if the probe in an unfilled sensor unit or the complex formed by the target and the probe in a filled sensor unit has a characteristic frequency that matches any one of the frequencies f1, f2 or a combination thereof, the probe or the complex will cause such frequency to change and the change of frequency is then detected by detector 70 and analyzed by detector circuit 80 for detecting the presence or absence of the target.
FIG. 7 is a cross-sectional view of a portion of the transducer 50 to illustrate the invention. As shown in FIG. 7, this portion of the transducer includes three probes 24 which are not bound to any targets. Therefore, if it is desired to detect the presence or absence of the target in a solution, for example, the frequencies of the AC sources 62, 64 may be tuned or set so that f1 or f2 or a combination thereof (referred to as detection frequency) matches the characteristic frequency of the probes 24 or that of a probe-target complex. It is possible to match a characteristic frequency much higher or lower than f1, f2 by using the sum or difference of f1, f2, or a combination of the two. This may be performed using a tuning process similar to that performed in ACSTM as described in U.S. Pat. No. 5,397,896. After the frequencies of the AC signals have been so tuned or set, such frequencies are applied to the transducer and the response or change in signal is measured. Then the transducer is placed in a flow cell 102 of FIG. 6 and the fluid to be tested is then injected through the inlet port 104 and adequate time is allowed for equilibrium to be reached within the flow cell between the probes and the fluid. Transducer 50 is then again measured at said tuned frequency to record any change in amplitude of the response detected by the detector 70. The detection frequencies may be in the range of about 1 Hz to 45 GHz.
Where the detection frequency matches the characteristic frequency of the probes 24, a reduction in the amplitude of the signal detected by the detector 70 compared to that prior to the transducer being exposed to the fluid to be tested will indicate the presence of the target substance of the fluid, whereas an absence of the target is indicated by the fact that there is little or no change in detector signal. If the number of probes 24 adapted for binding to the particular target in transducer 50 is known, or if the binding of the probes to the target has been calibrated, it may be possible to deduce the concentration of the target in the fluid to be tested from the above-described measurements.
FIG. 8 is a schematic view of a portion of transducer 50 where the probes 24 in this portion are bound to the target 140. In this instance, the AC signals delivered by sources 62, 64 may be tuned as before to the characteristic frequency of the complex formed by probe 24 and target 140. In this manner, detector 70 may be used to detect the presence or absence of the target in the fluid to be tested where a lack of change in signal will indicate the lack of target, while a change in signal will indicate its presence. The complex is formed again by placing the transducer in flow cell 102 and feeding the fluid to be tested into the flow cell as described above in reference to FIG. 7.
In some situations, the target to be detected may be of such a nature that it is difficult to detect a probe that will bind to it or to detect the complex formed by the probe and the target. In such circumstances, it may be desirable first to label the target 140 by means of a label 142 to yield a labelled target 144. The operator then has the choice of either detecting the presence of the labelled target 144 by having AC sources 62, 64 so that f1, f2 or a combination thereof matches the characteristic frequency of the complex formed by probe 24 and labelled target 144, or by simply detecting the label 142, which is more likely to be the case. In one embodiment, a labelled target 144 does not need to include the main target 140. It simply needs to be able to bind to the probe.
The scheme of this invention may also be used to detect the binding constant (affinity) and/or concentration of a particular target in a fluid. It is possible to use the above described transducer to measure the binding constants of the probe to the target and/or the concentration of the target substance. For example, a target solution of known concentration is first supplied to the transducer to reach equilibrium with the probes. AC signals are then transmitted to the probes and their complexes in the transducer in the manner described above to measure the responses at each of the locations of interest. Then a solution of the target at a higher known concentration than before is fed to the same transducer to again reach equilibrium with the probes and the response of the probes and complexes formed are again measured at the locations of interest in the manner described above. This process can be repeated further. A comparison of the two or more responses will yield the binding constants of the probes 24.
To increase the range of targets that can be detected, probes that bind to different targets may be employed in the same transducer. This is illustrated in FIGS. 10 and 11. As shown in FIG. 10, where the probes 24x, 24y, 24z have the same binding constant or affinity for the target to be measured, then transducer 50 will function essentially in the same manner as that described above in reference to FIGS. 7-9 for detecting the presence or absence or the concentration of the target. However, the groups of probes such as 24x, 24y, 24z may be made such that they have different affinities or binding constants to the target at issue. As shown in FIG. 10, probes 24z has the highest affinity or binding constant to the target while probes 24x do not significantly bind to the target at all while probes 24y are somewhere in between. The process described above for measuring binding constants can then be used to yield the binding constants of the various different probes 24x, 24y, 24z. Once the binding constants of the probes for a particular target have been determined, the user can then determine the concentration of the target in a fluid by binding the target to the probes as described and measuring the response by transmitting AC signals thereto and measuring the response.
Alternatively, a qualitative indication of the relative affinity or binding constant of the different probes to a given target may be determined by feeding a solution containing the target to the transducer and measuring the response at each of the probes shown.
The configuration in FIGS. 10 and 11 may also be used for verification of results, where the probes 24x, 24y, 24z have the same affinity for a particular target. The number of probe locations where target is bound in FIG. 10 may be counted in a first measurement. Then a fluid with an abundance of labelled target is caused to contact the unfilled probe locations to fill all the unfilled locations, and the number of locations with labelled targets are again counted in a second measurement to verify the accuracy of the first measurement if the total number of probe locations is known. Alternatively by counting the sites filled with labelled compounds, the number of sites where the unlabelled target is bound can be deduced.
The label 142 referred to above in FIG. 9 and in FIG. 11 may be a metallic material, such as a gold colloid which may be attached to the target by means of thiol gold chemistry or streptavidin biotin or other methods known to those skilled in the art.
In the construction of the above-described transducer 50 in FIGS. 1, 2A and 2B, it is desirable for the transmission lines 32, 42 to be suitable for transmitting the AC signals of the desired frequencies. For this purpose, it may be desirable first to determine the characteristic frequency of the substance to be detected, such as the characteristic frequencies of one or more different probes, complexes formed by the probes and targets, or complexes formed by probes and labelled targets. A characteristic frequency of a probe, or a complex of the type referred to above can be determined by means of an ACSTM in the manner such as that described in U.S. Pat. No. 5,397,896. If metal particles are used for labelling the target, tuning is less of an issue since the metallic label will cause a strong response irrespective of the frequency of the AC signal on the transmission lines.
In case there are variations in the characteristics of probes 24, it may be desirable to determine a standard threshold for the probes. This can be done by comparing the responses at or close to two sites where similar probes are located when AC signals are applied to the two sites. Then the threshold is applied to the response detected at the same or other locations.
Instead of using sets of parallel transmission wires or other elongated conductors as in FIGS. 2A, 2B, a two-dimensional array of electrically conductive probes may be employed instead where each of the probes will function in the same manner as that of an ACSTM for transmitting and/or for detecting signals. Such an embodiment is illustrated in FIG. 12. For such a transducer, a single AC source instead of two sources will be adequate when used with a single multiplexer for applying the AC signals sequentially to each of the electrically conductive probe tips of the two-dimensional array of probes. The above probe tips can be placed on transmission lines 32 and/or 42 on one or both sides of the device. Addressing is still at the probed unit 24a by applying AC frequencies to transmission lines 32a, 42a, but the signal is enhanced by the use of these microfabricated probe tips.
The embodiment of FIGS. 2B and 2C is advantageous over that of FIG. 12 since it greatly simplifies the construction of the transducer. Since each probe location can be addressed by the intersection of a horizontal and a vertical transmission line, only 2,000 transmission lines will be adequate for addressing a total of one million intersection probe locations. Furthermore, with the state of the art semiconductor fabrication technology, the spacing between adjacent lines can be as small as one micron or less, so that a one square centimeter transducer can accommodate about one million probe locations for detection. The transducer of FIGS. 2A and 2B and 12 are also advantageous since there are no moving parts, in contrast to the devices for detecting fluorescently labelled molecules employing microscopes. These devices are also advantageous over prior art fluorescent based detection systems employing charge coupled devices because of the superior resolution that can be achieved by this invention.
While the invention has been described above by reference to various embodiments, it will be understood that modifications and changes may be made without departing from the scope of the invention which is to be defined only by the appended claims and their equivalents.
|Patente citada||Fecha de presentación||Fecha de publicación||Solicitante||Título|
|US4905701 *||15 Jun 1988||6 Mar 1990||National Research Development Corporation||Apparatus and method for detecting small changes in attached mass of piezoelectric devices used as sensors|
|US5143854 *||7 Mar 1990||1 Sep 1992||Affymax Technologies N.V.||Large scale photolithographic solid phase synthesis of polypeptides and receptor binding screening thereof|
|US5151110 *||11 Sep 1990||29 Sep 1992||University Of New Mexico||Molecular sieve sensors for selective detection at the nanogram level|
|US5192507 *||4 Mar 1991||9 Mar 1993||Arthur D. Little, Inc.||Receptor-based biosensors|
|US5324633 *||22 Nov 1991||28 Jun 1994||Affymax Technologies N.V.||Method and apparatus for measuring binding affinity|
|US5397896 *||15 Jul 1993||14 Mar 1995||Penn State Research Foundation And Biotechnology Research And Development Corporation||Multiple source and detection frequencies in detecting threshold phenomena associated with and/or atomic or molecular spectra|
|US5412087 *||24 Abr 1992||2 May 1995||Affymax Technologies N.V.||Spatially-addressable immobilization of oligonucleotides and other biological polymers on surfaces|
|US5445934 *||30 Sep 1992||29 Ago 1995||Affymax Technologies N.V.||Array of oligonucleotides on a solid substrate|
|US5532128 *||12 Dic 1994||2 Jul 1996||Houston Advanced Research Center||Multi-site detection apparatus|
|US5656428 *||8 Sep 1994||12 Ago 1997||Biode, Inc.||Homogeneous bioassay using acoustic emission spectroscopy|
|EP0640832A2 *||30 Ago 1994||1 Mar 1995||Hughes Aircraft Company||Electrochemical immunosensor system|
|WO1992010587A1 *||6 Dic 1991||25 Jun 1992||Affymax Technologies N.V.||Sequencing of surface immobilized polymers utilizing microfluorescence detection|
|WO1993009668A1 *||20 Nov 1992||27 May 1993||Affymax Technology N.V.||Combinatorial strategies for polymer synthesis|
|WO1993017339A1 *||19 Feb 1993||2 Sep 1993||Thomson-Csf||Molecular sensor|
|WO1993022680A1 *||21 Abr 1993||11 Nov 1993||Affymax Technologies N.V.||Spatially-addressable immobilization of oligonucleotides and other biological polymers on surfaces|
|WO1995011995A1 *||26 Oct 1994||4 May 1995||Affymax Technologies N.V.||Arrays of nucleic acid probes on biological chips|
|WO1995022058A1 *||9 Feb 1995||17 Ago 1995||Affymax Technologies N.V.||Method and apparatus for detection of fluorescently labeled materials|
|1||*||International Search Report by the European Patent Office mailed Dec. 4, 1997.|
|Patente citante||Fecha de presentación||Fecha de publicación||Solicitante||Título|
|US6208553||1 Jul 1999||27 Mar 2001||The Regents Of The University Of California||High density non-volatile memory device incorporating thiol-derivatized porphyrins|
|US6212093||14 Ene 2000||3 Abr 2001||North Carolina State University||High-density non-volatile memory devices incorporating sandwich coordination compounds|
|US6272038||14 Ene 2000||7 Ago 2001||North Carolina State University||High-density non-volatile memory devices incorporating thiol-derivatized porphyrin trimers|
|US6287874||2 Ago 1999||11 Sep 2001||Signature Bioscience, Inc.||Methods for analyzing protein binding events|
|US6324091||14 Ene 2000||27 Nov 2001||The Regents Of The University Of California||Tightly coupled porphyrin macrocycles for molecular memory storage|
|US6338968||2 Ago 1999||15 Ene 2002||Signature Bioscience, Inc.||Method and apparatus for detecting molecular binding events|
|US6340568||19 Abr 2001||22 Ene 2002||Signature Bioscience, Inc.||Method for detecting and classifying nucleic acid hybridization|
|US6355491 *||17 Sep 1999||12 Mar 2002||Aviva Biosciences||Individually addressable micro-electromagnetic unit array chips|
|US6368795 *||1 Feb 1999||9 Abr 2002||Signature Bioscience, Inc.||Bio-assay device and test system for detecting molecular binding events|
|US6376258 *||10 Ene 2000||23 Abr 2002||Signature Bioscience, Inc.||Resonant bio-assay device and test system for detecting molecular binding events|
|US6381169||1 Jul 1999||30 Abr 2002||The Regents Of The University Of California||High density non-volatile memory device|
|US6395480 *||1 Feb 1999||28 May 2002||Signature Bioscience, Inc.||Computer program and database structure for detecting molecular binding events|
|US6451942||28 Jun 2000||17 Sep 2002||North Carolina State University||Substrates carrying polymers of linked sandwich coordination compounds and methods of use thereof|
|US6461808||12 Jun 2001||8 Oct 2002||Signature Bioscience, Inc.||Pipette-loaded bioassay assembly for detecting molecular or cellular events|
|US6478938 *||14 Jun 2000||12 Nov 2002||Bio Digit Laboratories Corporation||Electrochemical membrane strip biosensor|
|US6485905 *||2 Ago 1999||26 Nov 2002||Signature Bioscience, Inc.||Bio-assay device|
|US6566079||6 Ago 2001||20 May 2003||Signature Bioscience, Inc.||Methods for analyzing protein binding events|
|US6627461||18 Abr 2001||30 Sep 2003||Signature Bioscience, Inc.||Method and apparatus for detection of molecular events using temperature control of detection environment|
|US6649402||22 Jun 2001||18 Nov 2003||Wisconsin Alumni Research Foundation||Microfabricated microbial growth assay method and apparatus|
|US6657884||18 Ene 2002||2 Dic 2003||The Regents Of The University Of California||High density non-volatile memory device|
|US6716642||10 Oct 2000||6 Abr 2004||Aviva Biosciences Corporation||Individually addressable micro-electromagnetic unit array chips in horizontal configurations|
|US6728129||19 Feb 2002||27 Abr 2004||The Regents Of The University Of California||Multistate triple-decker dyads in three distinct architectures for information storage applications|
|US6777516||12 Jul 2002||17 Ago 2004||North Carolina State University||Substrates carrying polymers of linked sandwich coordination compounds and methods of use thereof|
|US6801029||11 Oct 2002||5 Oct 2004||Wisconsin Alumni Research Foundation||Microwave dielectric spectroscopy method and apparatus|
|US6806050||18 Sep 2001||19 Oct 2004||Aviva Biosciences||Individually addressable micro-electromagnetic unit array chips|
|US6921475||14 Mar 2002||26 Jul 2005||The Regents Of The University Of California||Open circuit potential amperometry and voltammetry|
|US7042755||28 Jun 2000||9 May 2006||The Regents Of The University Of California||High density non-volatile memory device|
|US7061791||25 Nov 2003||13 Jun 2006||The Regents Of The University Of California||High density molecular memory device|
|US7179587||27 Nov 2002||20 Feb 2007||Wisconsin Alumni Research Foundation||Method and apparatus for high frequency interfacing to biochemical membranes|
|US7309875 *||22 Nov 2004||18 Dic 2007||Hewlett-Packard Development Company, L.P.||Nanocrystal protective layer for crossbar molecular electronic devices|
|US7518905||3 Nov 2005||14 Abr 2009||The Regents Of The University Of California||High density memory device|
|US7723029||15 Jun 2005||25 May 2010||Aviva Biosciences Corporation||Biochips including ion transport detecting structures and methods of use|
|US7826250||7 Abr 2005||2 Nov 2010||North Carolina State Univeristy||Open circuit potential amperometry and voltammetry|
|US7968305||22 Mar 2002||28 Jun 2011||Aviva Biosciences Corporation||Biochips including ion transport detecting structures and methods of use|
|US9146221||13 Mar 2013||29 Sep 2015||Aviva Biosciences Corporation||High-density ion transport measurement biochip devices and methods|
|US20020177175 *||13 Ago 2001||28 Nov 2002||Hefti John J.||Coplanar waveguide biosensor for detecting molecular or cellular events|
|US20020180446 *||14 Mar 2002||5 Dic 2002||The Regents Of The University Of California Office Of Technology Transfer||Open circuit potential amperometry and voltammetry|
|US20020182627 *||22 Mar 2002||5 Dic 2002||Xiaobo Wang||Biochips including ion transport detecting strucutres and methods of use|
|US20030032000 *||13 Ago 2001||13 Feb 2003||Signature Bioscience Inc.||Method for analyzing cellular events|
|US20030032067 *||10 Sep 2002||13 Feb 2003||Signature Bioscience Inc.||Test systems and sensors for detecting molecular binding events|
|US20030090276 *||11 Oct 2002||15 May 2003||Weide Daniel W. Van Der||Microwave dielectric spectroscopy method and apparatus|
|US20030104229 *||12 Jul 2002||5 Jun 2003||Junzhong Li||Substrates carrying polymers of linked sandwich coordination compounds and methods of use thereof|
|US20030129737 *||27 Nov 2002||10 Jul 2003||Van Der Weide Daniel W.||Method and apparatus for high frequency interfacing to biochemical membranes|
|US20030169618 *||19 Feb 2002||11 Sep 2003||The Regents Of The University Of California Office Of Technology Transfer||Multistate triple-decker dyads in three distinct architectures for information storage applications|
|US20040077105 *||1 Dic 2003||22 Abr 2004||Lei Wu||Individually addressable micro-electromagnetic unit array chips in horizontal configurations|
|US20040146849 *||16 Ago 2003||29 Jul 2004||Mingxian Huang||Biochips including ion transport detecting structures and methods of use|
|US20040157263 *||25 Jun 2003||12 Ago 2004||Bayer Aktiengesellschaft,||Method for impedimetric detection of one or more analytes in a sample, and device for use therin|
|US20050009004 *||20 Ene 2004||13 Ene 2005||Jia Xu||Apparatus including ion transport detecting structures and methods of use|
|US20050041494 *||25 Nov 2003||24 Feb 2005||The Regents Of The University Of California And North Carolina State University||High density non-volatile memory device|
|US20050058990 *||1 Jun 2004||17 Mar 2005||Antonio Guia||Biochip devices for ion transport measurement, methods of manufacture, and methods of use|
|US20050196746 *||10 Ene 2005||8 Sep 2005||Jia Xu||High-density ion transport measurement biochip devices and methods|
|US20050266478 *||15 Jun 2005||1 Dic 2005||Mingxian Huang||Biochips including ion transport detecting structures and methods of use|
|US20060029955 *||5 Jul 2005||9 Feb 2006||Antonio Guia||High-density ion transport measurement biochip devices and methods|
|US20060108577 *||22 Nov 2004||25 May 2006||Ohlberg Douglas A||Nanocrystal protective layer for crossbar molecular electronic devices|
|US20060209587 *||3 Nov 2005||21 Sep 2006||The Regents Of The University Of California||High density memory device|
|US20060238696 *||20 Abr 2005||26 Oct 2006||Chien-Hui Wen||Method of aligning negative dielectric anisotropic liquid crystals|
|US20080286750 *||20 Ago 2007||20 Nov 2008||Aviva Biosciences Corporation||Apparatus including ion transport detecting structures and methods of use|
|US20090209029 *||18 Sep 2008||20 Ago 2009||Antonio Guia||High-density ion transport measurement biochip devices and methods|
|US20110015088 *||21 Jun 2010||20 Ene 2011||Rensselaer Polytechnic Institute||Biocatalytic solgel microarrays|
|DE10228260A1 *||25 Jun 2002||22 Ene 2004||Bayer Ag||Methode und Vorrichtung zum impedimetrischen Nachweis eines oder mehrerer Analyten in einer Probe|
|EP1451357A1 *||1 Nov 2002||1 Sep 2004||Rensselaer Polytechnic Institute||Biocatalytic solgel microarrays|
|EP1451357A4 *||1 Nov 2002||26 Oct 2005||Univ California||Biocatalytic solgel microarrays|
|EP2287330A1 *||1 Nov 2002||23 Feb 2011||Rensselaer Polytechnic Institute||Biocatalytic Solgel Microarrays|
|WO2001009381A2 *||27 Jul 2000||8 Feb 2001||Signature Bioscience, Inc.||Methods of nucleic acid analysis by detecting molecular binding events|
|WO2001009381A3 *||27 Jul 2000||2 May 2002||Signature Bioscience Inc||Methods of nucleic acid analysis by detecting molecular binding events|
|WO2001020329A2 *||27 Jul 2000||22 Mar 2001||Signature Bioscience, Inc.||Test systems and sensors for detecting molecular binding events|
|WO2001020329A3 *||27 Jul 2000||14 Feb 2002||Signature Bioscience Inc||Test systems and sensors for detecting molecular binding events|
|WO2002077259A2 *||22 Mar 2002||3 Oct 2002||Aviva Biosciences Corporation||Biochips including ion transport detecting structures and methods of use|
|WO2002077259A3 *||22 Mar 2002||14 Nov 2002||Aviva Biosciences Corp||Biochips including ion transport detecting structures and methods of use|
|Clasificación de EE.UU.||435/6.12, 435/7.9, 435/5, 435/16, 435/7.1, 435/287.2, 977/852, 435/287.1, 436/527, 204/400, 435/6.13|
|Clasificación cooperativa||Y10S977/852, G01N33/54373|
|3 Jul 1997||AS||Assignment|
Owner name: BIOTECHNOLOGY RESEARCH AND DEVELOPMENT CORPORATION
Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:PENN STATE RESEARCH FOUNDATION, THE;REEL/FRAME:008590/0056
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Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:WEISS, PAUL S.;REEL/FRAME:008590/0044
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Owner name: PENN STATE RESEARCH FOUNDATION, THE, PENNSYLVANIA
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Effective date: 19970527
|8 Jul 2002||FPAY||Fee payment|
Year of fee payment: 4
|2 Ago 2006||REMI||Maintenance fee reminder mailed|
|12 Ene 2007||LAPS||Lapse for failure to pay maintenance fees|
|13 Mar 2007||FP||Expired due to failure to pay maintenance fee|
Effective date: 20070112